Connecting Electrical Leads to Piezo Elements

The general soldering procedure and materials recommendations presented here are suitable for applying electrical connections to most APCI piezoelectric ceramic elements. To minimize the effects of heat on the piezoelectric properties of the ceramic, strive to keep the soldering time to 3 seconds or less. APCI can supply wire leads upon request.

Remember that thermal energy introduced into a piezoelectric ceramic element by soldering an electrode to it will generate an electrical charge in the element. To avoid the unpleasant consequences associated with discharging a piezoelectric ceramic element, apply solder to the element with the element in short-circuit conditions.

General Soldering Procedure
Equipment and Materials

Soldering iron (275°C - 300°C / 15W)
Solder (SN 62: 62% tin / 36% lead / 2% silver, 0.032" diameter)
Flux (active rosin) (Kestor 1544 or equivalent - no ZnCl or other corrosive agents)
Leads (common sizes 28AWG-32AWG)
Small, sharp blade (X-acto^® knife or equivalent)^{^®}
Solvent (for removing excess flux)
Cotton swabs

Procedure

Turn on the soldering iron and allow it to stabilize at 275°C - 300°C.
If the ceramic element has a protective coating (e.g., a Stripe™ actuator), carefully use the X-acto knife to remove the coating from areas where the leads are to be attached. For some elements (e.g., a Stripe actuator), this will expose the (silver) electrode. DO NOT remove the electrode.
Wipe the prepared surface with solvent and allow it to dry.
Flux and tin the wire with solder.
Place a small amount of flux on the wire and on the area to be soldered.
Melt a small amount of solder onto the soldering iron tip.
Place the wire on the surface in the desired position.
Place the iron with solder on the wire and surface. Hold for 1 - 2 seconds, then remove the iron. Solder should flow from the iron to the wire and surface. Allow the solder joint to cool before moving the wire.
Repeat steps 2 - 8 for each connection.
Clean the solder joint(s) with solvent.